Abstract: In this study, the tertiary and secondary structures of Patatin under different physico-chemical treatments were investigated by fluorescence and circular dichrosim. Patatin was rich in α-helix at p H4 ~ 5, but the α-helix was gradually instead by the β-sheet at p H6⁹.With the increasing p H, the strength of fluorescence became apparently lower.A blue shift in the maximum emission wavelength was observed, and the effect of p H on struction was reversible. Patatin was rich in β-sheet from 20 ℃ to 60 ℃.When the temperature reached to 80 ℃, the random coil content reached to maximum.With the increasing temperature, the fluorescence intensity decreased signifcantly. A red shift in the maximum emission wavelength was observed and the fluorescence intensity decreased in Patatin treated by DTT but increased by urea.A red shift in the maximum emission wavelength was observed, and the β-sheet gradually instead by the random coil under the condition of DTT and urea.